• Title/Summary/Keyword: Time trend analysis

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A Study on Trend Impact Analysis Based of Adaptive Neuro-Fuzzy Inference System

  • Yong-Gil Kim;Kang-Yeon Lee
    • International journal of advanced smart convergence
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    • v.12 no.1
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    • pp.199-207
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    • 2023
  • Trend Impact Analysis is a prominent hybrid method has been used in future studies with a modified surprise- free forecast. It considers experts' perceptions about how future events may change the surprise-free forecast. It is an advanced forecasting tool used in futures studies for identifying, understanding and analyzing the consequences of unprecedented events on future trends. In this paper, we propose an advanced mechanism to generate more justifiable estimates to the probability of occurrence of an unprecedented event as a function of time with different degrees of severity using adaptive neuro-fuzzy inference system (ANFIS). The key idea of the paper is to enhance the generic process of reasoning with fuzzy logic and neural network by adding the additional step of attributes simulation, as unprecedented events do not occur all of a sudden but rather their occurrence is affected by change in the values of a set of attributes. An ANFIS approach is used to identify the occurrence and severity of an event, depending on the values of its trigger attributes.

Comparative and analysis of multimedia author tools (멀티미디어 저작도구의 비교.분석)

  • Kwon Oh-Tack;Hong Dong-Heon
    • Management & Information Systems Review
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    • v.2
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    • pp.23-46
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    • 1998
  • In this paper, comparative and analysis of multimedia author tools for to proper compatible multimedia author tools on multimedia author tools function and usage, and which breach of contract each author tools specific property prepare to forecast future multimedia expansion trend on information technology expansion. Multimedia essential element is hardware(storage, digital video, CD), software, sound, hypertext and hypermedia etc. Analysis criteria of multimedia author tools is programming environment, which are card, script, icon, time method.

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Time Series Analysis of Intellectual Structure and Research Trend Changes in the Field of Library and Information Science: 2003 to 2017 (문헌정보학 분야의 지적구조 및 연구 동향 변화에 대한 시계열 분석: 2003년부터 2017년까지)

  • Choi, Hyung Wook;Choi, Ye-Jin;Nam, So-Yeon
    • Journal of the Korean Society for information Management
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    • v.35 no.2
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    • pp.89-114
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    • 2018
  • Research on changes in research trends in academic disciplines is a method that enables observation of not only the detailed research subject and structure of the field but also the state of change in the flow of time. Therefore, in this study, in order to observe the changes of research trend in library and information science field in Korea, co-word analysis was conducted with Korean author keywords from three types of journals which were listed in the Korea Citation Index(KCI) and have top citation impact factor were selected. For the time series analysis, the 15-year research period was accumulated in 5-years units, and divided into 2003~2007, 2003~2012, and 2003~2017. The keywords which limited to the frequency of appearance 10 or more, respectively, were analyzed and visualized. As a result of the analysis, during the period from 2003 to 2007, the intellectual structure composed with 25 keywords and 8 areas was confirmed, and during the period from 2003 to 2012, the structure composed by 3 areas 17 sub-areas with 76 keywords was confirmed. Also, the intellectual structure during the period from 2003 to 2017 was crowded into 6 areas 32 consisting of a total of 132 keywords. As a result of comprehensive period analysis, in the field of library and information science in Korea, over the past 15 years, new keywords have been added for each period, and detailed topics have also been subdivided and gradually segmented and expanded.

A Study on Reliability Growth through Failure Analysis by Operational Data of Avionic Equipments (항공전자장비의 운용자료 분석을 통한 신뢰성 성장 연구)

  • Jo, In-Tak;Lee, Sang-Cheon;Park, Jong Hun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.36 no.4
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    • pp.100-108
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    • 2013
  • In aerospace industry, MTBF (Mean Time Between Failure) and MFTBF (Mean Flight Time Between Failure) are generally used for reliability analysis. So far, especially to Korean military aircraft, MFTBF of avionic equipments is predicted by MIL-HDBK-217 and MIL-HDBK-338, however, the predicted MFTBF by military standard has a wide discrepancy to that of real-world operation, which leads to overstock and increase operation cost. This study analyzes operational data of avionic equipments. Operational MFTBF, which is calculated from operational data, is compared with predicted MFTBF calculated conventionally by military standard. In addition, failure rate trend is investigated to verify reliability growth in operational data, the investigation shows that failure rate curve from operational data has somewhat pattern with decreased failure rate and constant failure rate.

A Nonstationary Frequency Analysis of Extreme Wind Speed in Jeju using Bayesian Approach (베이지안 기법을 이용한 제주지역 극치풍속의 비정상성 빈도해석)

  • Kim, Kyoungmin;Kwon, Hyun-Han;Kwon, Soon-Duck
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.667-673
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    • 2019
  • Global warming may accelerate climate change and may increase disaster caused by strong winds. This research studied a method for a nonstationary frequency analysis considering the linear trend over time. The Bayesian method was used to estimate the posterior distribution of the parameters for the extreme value distribution of the annual maximum wind speed at Jeju Airport. The nonstationary frequency analysis was performed based on the Monte Carlo Markov Chain simulation and the Gibbs sampling. The estimated wind speeds by nonstationary frequency analysis was larger than those by stationary analysis. The conventional frequency analysis procedure assuming stationarity is likely to underestimate the future design wind speed in the region where statistically significant trend exists.

Stability Evaluation of National Reference Standards for Blood Products in Korea

  • Park, Tae Jun;Choi, Chan Woong;Oh, Ho Kyung;Kim, Jae Ok;Kim, Byung Kuk;Kang, Hyun Kyung;Kwon, Eun Jeong;Gweon, Eun Jeong;Park, Sang Jin;Kang, Ho Il;Jung, Ki Kyung;Park, Sang Mi;Kim, Ji Hye;Han, Ki Won;Jeong, Ja Young
    • Toxicological Research
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    • v.33 no.3
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    • pp.225-231
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    • 2017
  • National reference standards (NRSs) for biologics are established through potency estimation by a multi-center joint study of standard materials used in the approval process for national lot release and quality control of vaccines, blood products, and other biologics. In this study, a stability evaluation was conducted to determine whether the potency of NRSs for six blood products was being maintained at a consistent level in Korea. The present study conducted real-time stability tests via in-vivo/in-vitro bioassay on NRSs for blood coagulation factor VIII concentrate (2nd standard), antithrombin concentrate, prekallikrein activator, anti-hepatitis B immunoglobulin, blood coagulation factor IX concentrate, and anti-tetanus human immunoglobulin, as well as a trend analysis using cumulative annual results. The real-time stability test results showed that the mean potency of six NRSs was all within the control limit. In the trend analysis, the potency of NRS for blood coagulation factor VIII concentrate (2nd standard) showed a decreasing trend, while the potency of all other products had been stably maintained. The present study confirmed that the mean potency of NRSs for six blood products had been stably maintained in Korea. The findings of the present study establish a foundation that can ensure the quality of NRSs for biologics in Korea, and it is expected to make a major contribution to the supply of high-quality biologics.

Does the Increasing Trend of Colorectal Cancer Incidence in Jeddah Reflect a Rise in the Kingdom of Saudi Arabia?

  • Mosli, Mahmoud H.;Al-Ahwal, Mahmoud S.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6285-6288
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    • 2012
  • Background: The aim of this study was to outline the trend in the incidence of colorectal cancer (CRC) in the city of Jeddah, Kingdom of Saudi Arabia (KSA), for comparison with previously published national CRC data. Materials and Methods: A retrospective data analysis was performed on all cases of CRC diagnosed between January 2000 and December 2006 amongst Saudi patients in Jeddah using data retrieved from the Saudi Cancer Registry (SCR). Descriptive analysis was performed and results were compared to national CRC data from the SCR. Results: In Jeddah, 644 cases of CRC were diagnosed during the time period, accounting for 15% of all CRC cases in KSA. Males were more commonly affected than females (58% versus 42%). The male preponderance of CRC was similar to that observed at a national level. In Jeddah, the incidence was higher among those >45 years (77.0%), and the mean age at diagnosis was 57 years. At diagnosis, 10% of patients presented with localized disease; 25% presented with distant metastasis and the remaining patients had various stages of regional extension. Adenocarcinomas accounted for 72% of cases. Statistical analysis did not reveal any clinically significant differences between cases diagnosed in Jeddah and those diagnosed throughout KSA. Conclusions: The increased trend in the incidence of CRC in Jeddah between 2000 and 2006 mirrors the recent trend in KSA. This highlights the magnitude of this healthcare hazard, not only in Jeddah, but also across the country and supports the need for preventive measures and early detection of the disease.

Long-term Trend Analysis of Major Tributaries of Nakdong River Using Water Quality Index (수질지수를 이용한 낙동강 주요 지류지천의 장기 경향성 분석)

  • Park, Jaebeom;Kal, Byungseok;Kim, Sanghun
    • Journal of Wetlands Research
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    • v.20 no.3
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    • pp.201-209
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    • 2018
  • In this study, the water quality index was calculated using the water quality monitoring data of the major tributaries of the Nakdong River and long-term trend analysis was performed to identify the tributaries requiring priority management. We used a Real-Time Water Quality Index method implemented by the Ministry of Environment. Linear regression as a parametric method and Mann-Kendall Test and Sen Slope Test as a nonparametric method were applied for the trend analysis. The water quality index of major tributaries except for Migeon2 and Seokyo2 was in the range below Fair grade and there were no significant trends for the rest of the sites except Bukan, Chennae, Hogye, Yongdeok. Therefore, in order to improve the water quality of the main stream, management of the tributaries should be preceded.

A Study of Formative Aspects of Romanticism in Modern Wedding Dresses (현대 웨딩드레스에 나타난 로맨티시즘 조형성 -2010~2012년 대중스타의 웨딩드레스를 중심으로-)

  • Hong, Soo-Nam;Lee, Sang-Eun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.14 no.3
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    • pp.123-134
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    • 2012
  • As a mirror of its time, fashion exactly reflects the trend of today' s society. In addition, as a tool to satisfy our desire and express images, it brings diverse image changes in people's minds. This kind of pattern is frequently found in wedding images, especially in wedding dresses. When it comes to a wedding dress, in general, we often think of a modest and pure-white one. In modem times, however, people prefer a differentiated image which reflects their personality and ego. In other words, it is an important means of expressing their own personality by focusing on their active and personal aspects and getting away from the passive, stable and formative aspects in the past. These days, a combination of narcissism and eroticism is found on wedding dresses. This kind of trend has been expressed into romanticism. In terms of the latest sensitive wedding dress trend, unique and creative couture wedding dresses have appeared. Therefore, this study has classified this kind of trend into two categories; Formative and Design aspects. According to an analysis on the formative and design aspects of romanticism in wedding dresses, diverse characteristics were observed in shape, color, material and ornament in the Formative Aspect. In terms of design, the characteristics of sensuality, ornament, exoticism and compromise were observed.

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A Study on Trend Monitoring of a Long Endurance UAV s Gas Turbine to be Operated at Medium High Altitude

  • Kho, Seong-Hee;Ki, Ja-Young;Kong, Chang-Duk;Oh, Seong-Hwan;Kim, Ji-Hyun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.84-88
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    • 2008
  • The UAV propulsion system that will be operated for long time at more than 40,000ft altitude should have not only fuel flow minimization but also high reliability and durability. If this UAV propulsion system may have faults, it is not easy to recover the system from the abnormal, and hence an accurate diagnostic technology must be needed to keep the operational reliability. For this purpose, the development of the health monitoring system which can monitor remotely the engine condition should be required. In this study, a fuzzy trend monitoring method for detecting the engine faults including mechanical faults was proposed through analyzing performance trends of measurement data. The trend monitoring is an engine conditioning method which can find engine faults by monitoring important measuring parameters such as fuel flow, exhaust gas temperatures, rotational speeds, vibration and etc. Using engine condition database as an input to be generated by linear regression analysis of real engine instrument data, an application of the fuzzy logic in diagnostics estimated the cause of fault in each component. According to study results, it was confirmed that the proposed trend monitoring method can improve reliability and durability of the propulsion system for a long endurance UAV to be operated at medium altitude.

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